1. Field of the Invention
The field of the present invention is electromagnetically operated control systems of the type having an actuator means which is provided with an electromagnetic solenoid capable of exerting an electromagnetic force of the magnitude corresponding to the amount of electricity input to the solenoid, and a control circuit for controlling the amount of input electricity.
2. Description of the Prior Art
In a conventional system of the mentioned type, the electromagnetic solenoid generally has a single coil and the operation of the actuator means is controlled by controlling the amount of electricity input to the coil.
Such a conventional system, however, suffers from a problem that when the coil of the electromagnetic solenoid has a problem, the actuator means is difficult to be operated and therefore it is required to enhance the operational reliability of the coil which forms the electromagnetic solenoid, unavoidably leading to an increase in cost for assuring such reliability.